Department of Chemical and Biological Engineering, Drexel University, 3141 Chestnut St., Philadelphia, PA 19104, USA.
Anal Chim Acta. 2010 Jun 11;669(1-2):81-6. doi: 10.1016/j.aca.2010.04.056. Epub 2010 May 17.
We show for the first time that a piezoelectric-excited millimeter-sized cantilever (PEMC) sensor can detect five Cryptosporidium parvum oocysts in 25% milk in PBS background in a flow format (1 mL min(-1)). To improve sensitivity, a secondary antibody (murine IgM) was used to confirm the attachment of oocysts to the sensor. PEMC sensor is a resonant-mode cantilever sensor whose resonant frequency decreases when target analyte binds to its surface. The sensor was functionalized with Protein G, and then immobilized with goat polyclonal IgG anti-C. parvum for oocysts detection. In the dynamic range of 50-10,000 oocysts mL(-1) the sensor response is characterized by a semi-log relationship between resonant frequency response and C. parvum oocysts concentration. In 25% milk background, binding kinetics was slower and total sensor response was lower (approximately 45%) than in water-like buffer.
我们首次表明，在流动模式下（1 mL min(-1))，压电激励的毫米级悬臂梁（PEMC）传感器可以检测到 PBS 背景下 25%牛奶中的五个微小隐孢子虫卵囊。为了提高灵敏度，使用了第二种抗体（鼠源性 IgM）来确认卵囊附着在传感器上。PEMC 传感器是一种共振模式的悬臂梁传感器，当目标分析物与其表面结合时，其共振频率会降低。传感器用蛋白 G 功能化，然后用抗微小隐孢子虫的山羊多克隆 IgG 固定，用于检测卵囊。在 50-10,000 个卵囊 mL(-1)的动态范围内，传感器响应的特征是共振频率响应与微小隐孢子虫卵囊浓度之间呈半对数关系。在 25%牛奶背景下，结合动力学较慢，传感器总响应（约 45%）低于水状缓冲液。
